From b598796e9c927546cb9b6bcc5e3b21c8df7253fc Mon Sep 17 00:00:00 2001
From: Fardale <fardale+git@crans.org>
Date: Wed, 22 Jul 2020 21:01:04 +0200
Subject: [PATCH] break: remove klist in data

---
 src/data/CCFQueue.ml        | 128 ++++++++++++++++++------------------
 src/data/CCFQueue.mli       |  29 +++++---
 src/data/CCIntMap.ml        |  17 +++--
 src/data/CCIntMap.mli       |  13 ++--
 src/data/CCKTree.ml         |  13 ++--
 src/data/CCKTree.mli        |   5 +-
 src/data/CCSimple_queue.ml  |  32 ++-------
 src/data/CCSimple_queue.mli |  10 ---
 8 files changed, 113 insertions(+), 134 deletions(-)

diff --git a/src/data/CCFQueue.ml b/src/data/CCFQueue.ml
index 38173741..492ea512 100644
--- a/src/data/CCFQueue.ml
+++ b/src/data/CCFQueue.ml
@@ -3,8 +3,7 @@
 
 (** {1 Functional queues (fifo)} *)
 
-type 'a sequence = ('a -> unit) -> unit
-type 'a klist = unit -> [`Nil | `Cons of 'a * 'a klist]
+type 'a iter = ('a -> unit) -> unit
 type 'a equal = 'a -> 'a -> bool
 type 'a printer = Format.formatter -> 'a -> unit
 
@@ -95,7 +94,7 @@ let rec snoc : type a. a t -> a -> a t
   let q = List.fold_left snoc empty [1;2;3;4;5] in
   let q = tail q in
   let q = List.fold_left snoc q [6;7;8] in
-  let l = Iter.to_list (to_seq q) in
+  let l = Iter.to_list (to_iter q) in
   OUnit.assert_equal ~printer:pp_ilist [2;3;4;5;6;7;8] l
 *)
 
@@ -313,7 +312,7 @@ let tail q =
     l = [] || (of_list l |> tail |> to_list = List.tl l))
 *)
 
-let add_seq_front seq q =
+let add_iter_front seq q =
   let l = ref [] in
   (* reversed seq *)
   seq (fun x -> l := x :: !l);
@@ -321,38 +320,38 @@ let add_seq_front seq q =
 
 (*$Q
   Q.(pair (list int) (list int)) (fun (l1, l2) -> \
-    add_seq_front (Iter.of_list l1) (of_list l2) |> to_list = l1 @ l2)
+    add_iter_front (Iter.of_list l1) (of_list l2) |> to_list = l1 @ l2)
 *)
 
-let add_seq_back q seq =
+let add_iter_back q seq =
   let q = ref q in
   seq (fun x -> q := snoc !q x);
   !q
 
-let _digit_to_seq : type l. ('a, l) digit -> 'a sequence = fun d k -> match d with
+let _digit_to_iter : type l. ('a, l) digit -> 'a iter = fun d k -> match d with
   | Zero -> ()
   | One x -> k x
   | Two (x,y) -> k x; k y
   | Three (x,y,z) -> k x; k y; k z
 
-let rec to_seq : 'a. 'a t -> 'a sequence
+let rec to_iter : 'a. 'a t -> 'a iter
   = fun q k -> match q with
-    | Shallow d -> _digit_to_seq d k
+    | Shallow d -> _digit_to_iter d k
     | Deep (_, hd, lazy q', tail) ->
-      _digit_to_seq hd k;
-      to_seq q' (fun (x,y) -> k x; k y);
-      _digit_to_seq tail k
+      _digit_to_iter hd k;
+      to_iter q' (fun (x,y) -> k x; k y);
+      _digit_to_iter tail k
 
 (*$Q
   (Q.list Q.int) (fun l -> \
-    of_list l |> to_seq |> Iter.to_list = l)
+    of_list l |> to_iter |> Iter.to_list = l)
 *)
 
 let append q1 q2 =
   match q1, q2 with
     | Shallow Zero, _ -> q2
     | _, Shallow Zero -> q1
-    | _ -> add_seq_back q1 (to_seq q2)
+    | _ -> add_iter_back q1 (to_iter q2)
 
 (*$Q
   (Q.pair (Q.list Q.int)(Q.list Q.int)) (fun (l1,l2) -> \
@@ -360,13 +359,48 @@ let append q1 q2 =
 *)
 
 (*$R
-  let q1 = of_seq (Iter.of_list [1;2;3;4]) in
-  let q2 = of_seq (Iter.of_list [5;6;7;8]) in
+  let q1 = of_iter (Iter.of_list [1;2;3;4]) in
+  let q2 = of_iter (Iter.of_list [5;6;7;8]) in
   let q = append q1 q2 in
-  let l = Iter.to_list (to_seq q) in
+  let l = Iter.to_list (to_iter q) in
   OUnit.assert_equal ~printer:pp_ilist [1;2;3;4;5;6;7;8] l
 *)
 
+let add_seq_front seq q =
+  (* reversed seq *)
+  let l = Seq.fold_left (fun l elt -> elt::l ) [] seq in
+  List.fold_left (fun q x -> cons x q) q l
+
+(*$Q
+  Q.(pair (list int) (list int)) (fun (l1, l2) -> \
+    add_seq_front (CCList.to_seq l1) (of_list l2) |> to_list = l1 @ l2)
+*)
+
+let add_seq_back q seq =
+  Seq.fold_left (fun q x -> snoc q x) q seq
+
+let _digit_to_seq : type l. ('a, l) digit -> 'a Seq.t = fun d () -> match d with
+  | Zero -> Seq.Nil
+  | One x -> Seq.Cons (x, Seq.empty)
+  | Two (x,y) -> Seq.Cons (x, Seq.return y)
+  | Three (x,y,z) -> Seq.Cons (x, fun () -> Seq.Cons (y, Seq.return z))
+
+let rec to_seq : 'a. 'a t -> 'a Seq.t
+  = fun q -> match q with
+    | Shallow d -> _digit_to_seq d
+    | Deep (_, hd, lazy q', tail) ->
+      CCSeq.append (_digit_to_seq hd)
+        (CCSeq.append
+           (Seq.flat_map (fun (x,y) () -> Seq.Cons (x, Seq.return y) ) (to_seq q'))
+           (_digit_to_seq tail))
+
+let of_seq seq = add_seq_front seq empty
+
+(*$Q
+  (Q.list Q.int) (fun l -> \
+    of_list l |> to_seq |> List.of_seq = l)
+*)
+
 let _map_digit : type l. ('a -> 'b) -> ('a, l) digit -> ('b, l) digit = fun f d -> match d with
   | Zero -> Zero
   | One x -> One (f x)
@@ -407,25 +441,25 @@ let rec fold : 'a 'b. ('b -> 'a -> 'b) -> 'b -> 'a t -> 'b
 *)
 
 (*$R
-  let q = of_seq (Iter.of_list [1;2;3;4]) in
+  let q = of_iter (Iter.of_list [1;2;3;4]) in
   let n = fold (+) 0 q in
   OUnit.assert_equal 10 n;
 *)
 
-let iter f q = to_seq q f
+let iter f q = to_iter q f
 
 let of_list l = List.fold_left snoc empty l
 
 let to_list q =
   let l = ref [] in
-  to_seq q (fun x -> l := x :: !l);
+  to_iter q (fun x -> l := x :: !l);
   List.rev !l
 
-let of_seq seq = add_seq_front seq empty
+let of_iter seq = add_iter_front seq empty
 
 (*$Q
   (Q.list Q.int) (fun l -> \
-    Iter.of_list l |> of_seq |> to_list = l)
+    Iter.of_list l |> of_iter |> to_list = l)
 *)
 
 let rev q =
@@ -438,50 +472,14 @@ let rev q =
     of_list l |> rev |> to_list = List.rev l)
 *)
 
-let _nil () = `Nil
-let _single x cont () = `Cons (x, cont)
-let _double x y cont () = `Cons (x, _single y cont)
-let _triple x y z cont () = `Cons (x, _double y z cont)
+let rec _equal_seq eq l1 l2 = match l1(), l2() with
+  | Seq.Nil, Seq.Nil -> true
+  | Seq.Nil, _
+  | _, Seq.Nil -> false
+  | Seq.Cons(x1,l1'), Seq.Cons(x2,l2') ->
+    eq x1 x2 && _equal_seq eq l1' l2'
 
-let _digit_to_klist : type l. ('a, l) digit -> 'a klist -> 'a klist = fun d cont -> match d with
-  | Zero -> _nil
-  | One x -> _single x cont
-  | Two (x,y) -> _double x y cont
-  | Three (x,y,z) -> _triple x y z cont
-
-let rec _flat_klist : 'a. ('a * 'a) klist -> 'a klist -> 'a klist
-  = fun l cont () -> match l () with
-    | `Nil -> cont ()
-    | `Cons ((x,y),l') -> _double x y (_flat_klist l' cont) ()
-
-let to_klist q =
-  let rec aux : 'a. 'a t -> 'a klist -> 'a klist
-    = fun q cont () -> match q with
-      | Shallow d -> _digit_to_klist d cont ()
-      | Deep (_, hd, lazy q', tl) ->
-        _digit_to_klist hd
-          (_flat_klist
-             (aux q' _nil)
-             (_digit_to_klist tl cont))
-          ()
-  in
-  aux q _nil
-
-let of_klist l =
-  let rec seq l k = match l() with
-    | `Nil -> ()
-    | `Cons(x,l') -> k x; seq l' k
-  in
-  add_seq_front (seq l) empty
-
-let rec _equal_klist eq l1 l2 = match l1(), l2() with
-  | `Nil, `Nil -> true
-  | `Nil, _
-  | _, `Nil -> false
-  | `Cons(x1,l1'), `Cons(x2,l2') ->
-    eq x1 x2 && _equal_klist eq l1' l2'
-
-let equal eq q1 q2 = _equal_klist eq (to_klist q1) (to_klist q2)
+let equal eq q1 q2 = _equal_seq eq (to_seq q1) (to_seq q2)
 
 (*$T
   let q1 = 1 -- 10 and q2 = append (1 -- 5) (6 -- 10) in \
diff --git a/src/data/CCFQueue.mli b/src/data/CCFQueue.mli
index 4fce8b7d..190827a9 100644
--- a/src/data/CCFQueue.mli
+++ b/src/data/CCFQueue.mli
@@ -3,8 +3,7 @@
 
 (** {1 Functional queues} *)
 
-type 'a sequence = ('a -> unit) -> unit
-type 'a klist = unit -> [`Nil | `Cons of 'a * 'a klist]
+type 'a iter = ('a -> unit) -> unit
 type 'a equal = 'a -> 'a -> bool
 type 'a printer = Format.formatter -> 'a -> unit
 
@@ -117,15 +116,29 @@ val equal : 'a equal -> 'a t equal
 val of_list : 'a list -> 'a t
 val to_list : 'a t -> 'a list
 
-val add_seq_front : 'a sequence -> 'a t -> 'a t
+val add_iter_front : 'a iter -> 'a t -> 'a t
+(** @since NEXT_RELEASE *)
 
-val add_seq_back : 'a t -> 'a sequence -> 'a t
+val add_iter_back : 'a t -> 'a iter -> 'a t
+(** @since NEXT_RELEASE *)
 
-val to_seq : 'a t -> 'a sequence
-val of_seq : 'a sequence -> 'a t
+val to_iter : 'a t -> 'a iter
+(** @since NEXT_RELEASE *)
 
-val to_klist : 'a t -> 'a klist
-val of_klist : 'a klist -> 'a t
+val of_iter : 'a iter -> 'a t
+(** @since NEXT_RELEASE *)
+
+val add_seq_front : 'a Seq.t -> 'a t -> 'a t
+(** @since NEXT_RELEASE *)
+
+val add_seq_back : 'a t -> 'a Seq.t -> 'a t
+(** @since NEXT_RELEASE *)
+
+val to_seq : 'a t -> 'a Seq.t
+(** @since NEXT_RELEASE *)
+
+val of_seq : 'a Seq.t -> 'a t
+(** @since NEXT_RELEASE *)
 
 val (--) : int -> int -> int t
 (** [a -- b] is the integer range from [a] to [b], both included.
diff --git a/src/data/CCIntMap.ml b/src/data/CCIntMap.ml
index 5707b20a..1baada8e 100644
--- a/src/data/CCIntMap.ml
+++ b/src/data/CCIntMap.ml
@@ -579,7 +579,6 @@ let rec merge ~f t1 t2 : _ t =
 
 type 'a iter = ('a -> unit) -> unit
 type 'a gen = unit -> 'a option
-type 'a klist = unit -> [`Nil | `Cons of 'a * 'a klist]
 
 let add_list t l = List.fold_left (fun t (k,v) -> add k v t) t l
 
@@ -685,27 +684,27 @@ let compare ~cmp a b =
     (compare ~cmp:Stdlib.compare m1 m2 = 0) = equal ~eq:(=) m1 m2)
 *)
 
-let rec add_klist m l = match l() with
-  | `Nil -> m
-  | `Cons ((k,v), tl) -> add_klist (add k v m) tl
+let rec add_seq m l = match l() with
+  | Seq.Nil -> m
+  | Seq.Cons ((k,v), tl) -> add_seq (add k v m) tl
 
-let of_klist l = add_klist empty l
+let of_seq l = add_seq empty l
 
-let to_klist m =
+let to_seq m =
   (* [st]: stack of alternatives *)
   let rec explore st m () = match m with
     | E -> next st ()
-    | L (k,v) -> `Cons ((k, v), next st)
+    | L (k,v) -> Seq.Cons ((k, v), next st)
     | N (_, _, l, r) -> explore (r::st) l ()
   and next st () = match st with
-    | [] -> `Nil
+    | [] -> Seq.Nil
     | x :: st' -> explore st' x ()
   in
   next [m]
 
 (*$Q
   Q.(list (pair int bool)) (fun l -> \
-    let m = of_list l in equal ~eq:(=) m (m |> to_klist |> of_klist))
+    let m = of_list l in equal ~eq:(=) m (m |> to_seq |> of_seq))
 *)
 
 type 'a tree = unit -> [`Nil | `Node of 'a * 'a tree list]
diff --git a/src/data/CCIntMap.mli b/src/data/CCIntMap.mli
index 4173493b..7964bc7a 100644
--- a/src/data/CCIntMap.mli
+++ b/src/data/CCIntMap.mli
@@ -84,7 +84,6 @@ val merge :
 
 type 'a iter = ('a -> unit) -> unit
 type 'a gen = unit -> 'a option
-type 'a klist = unit -> [`Nil | `Cons of 'a * 'a klist]
 
 val add_list : 'a t -> (int * 'a) list -> 'a t
 
@@ -111,14 +110,14 @@ val of_gen : (int * 'a) gen -> 'a t
 val to_gen : 'a t -> (int * 'a) gen
 (** @since 0.13 *)
 
-val add_klist : 'a t -> (int * 'a) klist -> 'a t
-(** @since 0.13 *)
+val add_seq : 'a t -> (int * 'a) Seq.t -> 'a t
+(** @since NEXT_RELEASE *)
 
-val of_klist : (int * 'a) klist -> 'a t
-(** @since 0.13 *)
+val of_seq : (int * 'a) Seq.t -> 'a t
+(** @since NEXT_RELEASE *)
 
-val to_klist : 'a t -> (int * 'a) klist
-(** @since 0.13 *)
+val to_seq : 'a t -> (int * 'a) Seq.t
+(** @since NEXT_RELEASE *)
 
 type 'a tree = unit -> [`Nil | `Node of 'a * 'a tree list]
 
diff --git a/src/data/CCKTree.ml b/src/data/CCKTree.ml
index ede20047..1ae2d9e2 100644
--- a/src/data/CCKTree.ml
+++ b/src/data/CCKTree.ml
@@ -7,7 +7,6 @@
 
 type 'a sequence = ('a -> unit) -> unit
 type 'a gen = unit -> 'a option
-type 'a klist = unit -> [`Nil | `Cons of 'a * 'a klist]
 type 'a printer = Format.formatter -> 'a -> unit
 
 type +'a t = unit -> [`Nil | `Node of 'a * 'a t list]
@@ -79,12 +78,12 @@ let set_of_cmp (type elt) ~cmp () =
     method mem x = S.mem x s
   end
 
-let _nil () = `Nil
-let _cons x l = `Cons (x, l)
+let _nil () = Seq.Nil
+let _cons x l = Seq.Cons (x, l)
 
 let dfs ~pset t =
   let rec dfs pset stack () = match stack with
-    | [] -> `Nil
+    | [] -> Seq.Nil
     | `Explore t :: stack' ->
       begin match t() with
         | `Nil -> dfs pset stack' ()
@@ -136,7 +135,7 @@ end
 
 let bfs ~pset t =
   let rec bfs pset q () =
-    if FQ.is_empty q then `Nil
+    if FQ.is_empty q then Seq.Nil
     else
       let t, q' = FQ.pop_exn q in
       match t() with
@@ -156,8 +155,8 @@ let rec force t : ([`Nil | `Node of 'a * 'b list] as 'b) = match t() with
 
 let find ~pset f t =
   let rec _find_kl f l = match l() with
-    | `Nil -> None
-    | `Cons (x, l') ->
+    | Seq.Nil -> None
+    | Seq.Cons (x, l') ->
       match f x with
         | None -> _find_kl f l'
         | Some _ as res -> res
diff --git a/src/data/CCKTree.mli b/src/data/CCKTree.mli
index 3b161bae..9907e19d 100644
--- a/src/data/CCKTree.mli
+++ b/src/data/CCKTree.mli
@@ -7,7 +7,6 @@
 
 type 'a sequence = ('a -> unit) -> unit
 type 'a gen = unit -> 'a option
-type 'a klist = unit -> [`Nil | `Cons of 'a * 'a klist]
 type 'a printer = Format.formatter -> 'a -> unit
 
 (** {2 Basics} *)
@@ -60,10 +59,10 @@ end
 val set_of_cmp : cmp:('a -> 'a -> int) -> unit -> 'a pset
 (** Build a set structure given a total ordering. *)
 
-val dfs : pset:'a pset -> 'a t -> [ `Enter of 'a | `Exit of 'a ] klist
+val dfs : pset:'a pset -> 'a t -> [ `Enter of 'a | `Exit of 'a ] Seq.t
 (** Depth-first traversal of the tree. *)
 
-val bfs : pset:'a pset -> 'a t -> 'a klist
+val bfs : pset:'a pset -> 'a t -> 'a Seq.t
 (** Breadth-first traversal of the tree. *)
 
 val force : 'a t -> ([ `Nil | `Node of 'a * 'b list ] as 'b)
diff --git a/src/data/CCSimple_queue.ml b/src/data/CCSimple_queue.ml
index 9aa4e5dd..725048cb 100644
--- a/src/data/CCSimple_queue.ml
+++ b/src/data/CCSimple_queue.ml
@@ -6,7 +6,6 @@
 type 'a iter = ('a -> unit) -> unit
 type 'a sequence = ('a -> unit) -> unit
 type 'a printer = Format.formatter -> 'a -> unit
-type 'a klist = unit -> [`Nil | `Cons of 'a * 'a klist]
 type 'a gen = unit -> 'a option
 
 type 'a t = {
@@ -139,23 +138,6 @@ let to_seq q =
   in
   aux1 q.hd
 
-let rec klist_iter_ k f = match k() with
-  | `Nil -> ()
-  | `Cons (x,tl) -> f x; klist_iter_ tl f
-
-let add_klist q l = add_iter q (klist_iter_ l)
-let of_klist l = add_klist empty l
-
-let to_klist q =
-  let rec aux1 l () = match l with
-    | [] -> aux2 (List.rev q.tl) ()
-    | x :: tl -> `Cons (x, aux1 tl)
-  and aux2 l () = match l with
-    | [] -> `Nil
-    | x :: tl -> `Cons (x, aux2 tl)
-  in
-  aux1 q.hd
-
 let rec gen_iter g f = match g() with
   | None -> ()
   | Some x -> f x; gen_iter g f
@@ -174,14 +156,14 @@ let to_gen q =
   in
   aux
 
-let rec klist_equal eq l1 l2 = match l1(), l2() with
-  | `Nil, `Nil -> true
-  | `Nil, _
-  | _, `Nil -> false
-  | `Cons (x1,l1'), `Cons (x2,l2') ->
-    eq x1 x2 && klist_equal eq l1' l2'
+let rec seq_equal eq l1 l2 = match l1(), l2() with
+  | Seq.Nil, Seq.Nil -> true
+  | Seq.Nil, _
+  | _, Seq.Nil -> false
+  | Seq.Cons (x1,l1'), Seq.Cons (x2,l2') ->
+    eq x1 x2 && seq_equal eq l1' l2'
 
-let equal eq q1 q2 = klist_equal eq (to_klist q1) (to_klist q2)
+let equal eq q1 q2 = seq_equal eq (to_seq q1) (to_seq q2)
 
 (*$Q
   Q.(pair (list small_int)(list small_int)) (fun (l1,l2) -> \
diff --git a/src/data/CCSimple_queue.mli b/src/data/CCSimple_queue.mli
index 55e9d891..647b360a 100644
--- a/src/data/CCSimple_queue.mli
+++ b/src/data/CCSimple_queue.mli
@@ -16,7 +16,6 @@ type 'a iter = ('a -> unit) -> unit
     @since 2.8 *)
 
 type 'a printer = Format.formatter -> 'a -> unit
-type 'a klist = unit -> [`Nil | `Cons of 'a * 'a klist]
 type 'a gen = unit -> 'a option
 
 type +'a t
@@ -100,15 +99,6 @@ val of_seq : 'a Seq.t -> 'a t
 (** Renamed from [of_std_seq] since NEXT_RELEASE.
     @since NEXT_RELEASE *)
 
-val to_klist : 'a t -> 'a klist
-[@@ocaml.deprecated "use to_seq"]
-
-val add_klist : 'a t -> 'a klist -> 'a t
-[@@ocaml.deprecated "use add_seq"]
-
-val of_klist : 'a klist -> 'a t
-[@@ocaml.deprecated "use of_seq"]
-
 val of_gen : 'a gen -> 'a t
 val add_gen : 'a t -> 'a gen -> 'a t
 val to_gen : 'a t -> 'a gen